Such gear transmissions are known in many types, for example from published PCT application WO 86/05449 filed 12 Mar. 1985 by G. Bieber. Normally with other synchronized transmissions only the forward ranges are provided with synchronizing devices while the reverse speed ranges have a simple jaw clutch without any synchronizing device. Such transmissions are indeed simple in construction but their gears clash when shifted into reverse due to an excessively high speed differential between the shafts being shifted and the changing time is long since the clashing only slowly decreases the speed differences. In addition this gear-clashing subjects the teeth to wear so that they do not engage properly and eventually can not be shifted easily or at all because one tooth directly engages another.